Cleaning of CHF3 plasma-etched SiO2/SiN/Cu via structures with dilute hydrofluoric acid solutions

Kazuyoshi Ueno, Vincent M. Donnelly, Takamaro Kikkawa

Research output: Contribution to journalArticle

34 Citations (Scopus)

Abstract

After etching in a CHF3/Ar electron cyclotron resonance plasma, SiO2/SiN/Cu via structures for multilevel Cu interconnection were investigated with angle-resolved x-ray photoelectron spectroscopy. Photoelectron shadowing, determined by x-ray photoelectron spectroscopy takeoff angle, and electrostatic charging were used to determine the chemical composition and amount of contamination on the dielectric horizontal surfaces and via sidewalls, as well as on the Cu at the bottoms of the via holes. All surfaces were covered with one to two monolayers of a CFx layer (CF > CF2 > CF3). The dielectric surfaces were also covered with a small amount (∼0.1 monolayers) of Cu, and the Cu at the bottom of the via was contaminated with O (mainly CuO) and F. After cleaning with dilute HF solution, the dielectric surfaces were free of Cu and most of the F and C. CuO was also removed from the Cu surface by this treatment; however, Cu2O and CFx remained.

Original languageEnglish
Pages (from-to)2565-2572
Number of pages8
JournalJournal of the Electrochemical Society
Volume144
Issue number7
Publication statusPublished - 1997 Jul
Externally publishedYes

Fingerprint

Hydrofluoric Acid
Hydrofluoric acid
hydrofluoric acid
cleaning
Cleaning
Plasmas
Photoelectron spectroscopy
x ray spectroscopy
Monolayers
photoelectron spectroscopy
X rays
takeoff
Electron cyclotron resonance
Takeoff
electron cyclotron resonance
Photoelectrons
charging
Electrostatics
Etching
chemical composition

ASJC Scopus subject areas

  • Electrochemistry
  • Surfaces, Coatings and Films
  • Surfaces and Interfaces

Cite this

Cleaning of CHF3 plasma-etched SiO2/SiN/Cu via structures with dilute hydrofluoric acid solutions. / Ueno, Kazuyoshi; Donnelly, Vincent M.; Kikkawa, Takamaro.

In: Journal of the Electrochemical Society, Vol. 144, No. 7, 07.1997, p. 2565-2572.

Research output: Contribution to journalArticle

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